U.S. patent application number 10/393669 was filed with the patent office on 2003-09-25 for brush holder and manufacturing method thereof.
Invention is credited to Hirano, Yoshinobu, Masuda, Masakuni, Obata, Kenji.
Application Number | 20030178908 10/393669 |
Document ID | / |
Family ID | 28035737 |
Filed Date | 2003-09-25 |
United States Patent
Application |
20030178908 |
Kind Code |
A1 |
Hirano, Yoshinobu ; et
al. |
September 25, 2003 |
Brush holder and manufacturing method thereof
Abstract
A brush holder incorporates a terminal integral part, which has
a coupling portion. The coupling portion couples the terminals with
each other. The brush holder has a resin body and a plurality of
terminals. The resin body has an opening. The terminals are
embedded in the resin body. The terminals are coupled to each other
by the coupling portion as an integral part before being embedded
in the resin body. The coupling portion is exposed from the opening
of the resin body. The terminals are separated from each other by
cutting the coupling portion, which is exposed from the opening of
the resin body. A coating member coats the opening of the resin
body to insulate each terminal.
Inventors: |
Hirano, Yoshinobu;
(Toyohashi-shi, JP) ; Obata, Kenji; (Kosai-shi,
JP) ; Masuda, Masakuni; (Kosai-shi, JP) |
Correspondence
Address: |
Mr. Joseph A. Sawyer, Jr.
SAWYER LAW GROUP LLP
P. O. Box 51418
Palo Alto
CA
94303
US
|
Family ID: |
28035737 |
Appl. No.: |
10/393669 |
Filed: |
March 19, 2003 |
Current U.S.
Class: |
310/239 ;
310/71 |
Current CPC
Class: |
H01R 39/383 20130101;
Y10T 29/53143 20150115; Y10T 29/49119 20150115; H01R 39/38
20130101; H01R 39/388 20130101; H02K 5/143 20130101; Y10T 29/49009
20150115; H01R 43/24 20130101; H02K 7/1166 20130101; Y10T 29/49117
20150115; H02K 5/225 20130101; Y10T 29/49121 20150115 |
Class at
Publication: |
310/239 ;
310/71 |
International
Class: |
H02K 013/00; H02K
011/00; H01R 039/38 |
Foreign Application Data
Date |
Code |
Application Number |
Mar 22, 2002 |
JP |
2002-081728 |
Claims
1. A manufacturing method for a brush holder, wherein the brush
holder is located inside a motor housing and retains a brush, the
method comprising: forming a terminal integral part, which includes
a plurality of terminals and a coupling portion, wherein the
coupling portion couples the terminals with each other; molding a
resin body to embed the terminal integral part, wherein the resin
body forms at least part of the brush holder and has an opening
from which the coupling portion is exposed; separating the
terminals from each other by cutting the coupling portion, which is
exposed from the opening of the resin body; and coating the opening
of the resin body with a coating member to insulate the separated
terminals from each other.
2. The manufacturing method according to claim 1, wherein the
coating member is molded integrally with the resin body.
3. The manufacturing method according to claim 1, wherein the
coating member is attached to the resin body.
4. The manufacturing method according to claim 1, wherein the motor
housing has an opening, wherein the manufacturing method further
includes molding a sealing member integrally with the resin body to
seal the opening of the motor housing, and wherein the coating
member is made of the same material as that of the sealing member
and molded with the resin body.
5. The manufacturing method according to claim 1, wherein the motor
housing has an opening, wherein the manufacturing method further
includes molding a sealing member integrally with the resin body to
seal the opening of the motor housing, and wherein the coating
member is simultaneously molded with the sealing member.
6. The manufacturing method according to claim 1, wherein the
coating member is formed of elastic material.
7. The manufacturing method according to claim 6, wherein the
elastic material is elastomer.
8. The manufacturing method according to claim 1, wherein the brush
holder has a main body, which is located inside the motor housing
and retains the brush, an extended portion, which extends from the
main body to the outside of the motor housing, and a connector
portion, which is exposed outside the motor housing from the
extended portion, and wherein the coupling portion is located at a
position corresponding to at least one of the extended portion and
the connector portion.
9. The manufacturing method according to claim 1, wherein the brush
holder has a main body, which is located inside the motor housing
and retains the brush, an extended portion, which extends from the
main body to the outside of the motor housing, and a connector
portion, which is exposed outside the motor housing from the
extended portion, and wherein the coupling portion is one of
coupling portions located at positions associated with at least two
of the positions corresponding to the main body, the extended
portion, and the connector portion.
10. The manufacturing method according to claim 9, wherein the
connector portions are cut simultaneously.
11. The manufacturing method according to claim 1, wherein the
coupling portion is one of a plurality of coupling portions, and
wherein the coupling portions are exposed from the opening of the
resin body.
12. The manufacturing method according to claim 1, wherein the
motor housing includes a yoke housing and a gear housing, wherein
the yoke housing forms part of a motor main body, which rotates a
rotary shaft, wherein the gear housing accommodates a reduction
mechanism, which is assembled to the yoke housing and reduces
rotation of the rotary shaft, wherein the manufacturing method
further includes fixing the brush holder between the yoke housing
and the gear housing, and wherein the opening of the resin body and
the coating member are located at a portion of the brush holder,
which is held between the yoke housing and the gear housing.
13. A brush holder, which is located inside the motor housing and
retains a brush, wherein the brush holder incorporates a terminal
integral part, which has a coupling portion, and wherein the
coupling portion is located at a predetermined position and couples
the terminals with each other, the brush holder comprising: a resin
body forming at least part of the brush holder, wherein the resin
body has an opening; a plurality of terminals embedded in the resin
body, wherein the terminals are coupled to each other by the
coupling portion as an integral part before being embedded in the
resin body, wherein the coupling portion is exposed from the
opening of the resin body, and wherein the terminals are separated
from each other by cutting the coupling portion, which is exposed
from the opening of the resin body; and a coating member for
coating the opening of the resin body to insulate each
terminal.
14. The brush holder according to claim 13, wherein the coating
member is molded integrally with the resin body.
15. The brush holder according to claim 13, wherein the coating
member is attached to the resin body.
16. The brush holder according to claim 13, wherein the motor
housing has an opening, and the brush holder further includes a
sealing member, which seals the opening of the motor housing,
wherein the sealing member is molded integrally with the resin
body, and wherein the coating member is made of the same material
as that of the sealing member and molded with the resin body.
17. The brush holder according to claim 13, wherein the motor
housing has an opening, and the brush holder further includes a
sealing member, which seals the opening of the motor housing,
wherein the sealing member is molded integrally with the resin
body, and wherein the coating member is simultaneously molded with
the sealing member.
18. The brush holder according to claim 13, wherein the coating
member is formed of elastic material.
19. The brush holder according to claim 18, wherein the elastic
material is elastomer.
20. The brush holder according to claim 13, further comprising a
main body, which is located inside the motor housing and retains
the brush, an extended portion, which extends from the main body to
the outside of the motor housing, and a connector portion, which is
exposed outside the motor housing from the extended portion,
wherein the coupling portion is located at a position corresponding
to at least one of the extended portion and the connector
portion.
21. The brush holder according to claim 13, further comprising a
main body, which is located inside the motor housing retains the
brush, an extended portion, which extends from the main body to the
outside of the motor housing, and a connector portion, which is
exposed outside the motor housing from the extended portion,
wherein the coupling portion is one of coupling portions located at
positions associated with at least two of the positions
corresponding to the main body, the extended portion, and the
connector portion.
22. The brush holder according to claim 13, wherein the coupling
portion is one of a plurality of coupling portions, and wherein the
coupling portions are exposed from the opening of the resin
body.
23. The brush holder according to claim 22, wherein the connector
portions are cut at once.
24. The brush holder according to claim 13, wherein the motor
housing includes a yoke housing and a gear housing, wherein the
yoke housing forms part of a motor main body, which rotates a
rotary shaft, wherein the gear housing accommodates a reduction
mechanism, which is assembled to the yoke housing and reduces
rotation of the rotary shaft, wherein the brush holder is held and
fixed between the yoke housing and the gear housing, and wherein
the opening of the resin body and the coating member are located at
a portion of the brush holder, which is held between the yoke
housing and the gear housing.
Description
BACKGROUND OF THE INVENTION
[0001] The present invention relates to a brush holder used for a
motor and a manufacturing method of the brush holder.
[0002] A conventional brush holder is located inside a motor
housing and includes a main body, which retains brushes, and a
connector portion, which is integrally formed with the main body.
The connector portion is exposed from the motor housing and is
electrically connected to an external device. Terminals are
embedded in the brush holder and extend from the connector portion
to the main body of the brush holder.
[0003] The terminals include a first terminal, which receives power
supply from the outside, and a second terminal, which sends out
detection signals of a detector to the outside. The detector
includes, for example, a rotation sensor, which detects rotational
speed of the motor. The first and second terminals are apart from
each other at a predetermined interval at the main body and the
connector. In other words, the first and second terminals are
insulated from each other.
[0004] The brush holder is formed of resin by injection molding.
More specifically, resin is filled in a mold, with the first and
second terminals placed in the mold, to form the brush holder.
[0005] In a case when the brush holder is molded with separate
terminals placed in the mold, the procedure for placing the
terminals in the mold is complicated. Therefore, in the
conventional brush holder, a unit in which the terminals are
coupled to each other at predetermined portions is placed in the
mold. Then, resin is filled in the mold to form the brush holder.
After that, the coupling portions between the terminals are
cut.
[0006] The cut portions of the terminals are exposed from the brush
holder. Therefore, liquid could enter from the exposed portion.
Further, if any of the cut portions is in the vicinity of the
brushes, foreign objects (such as brush powder scattered from the
brushes) could enter from the exposed portion and cause a
short-circuit at the cut portion of the terminals.
SUMMARY OF THE INVENTION
[0007] Accordingly, it is an objective of the present invention to
provide a brush holder that reliably prevents short-circuit of
terminals and a manufacturing method of the brush holder.
[0008] To achieve the above objective, the present invention
provides a manufacturing method for a brush holder. The brush
holder is located inside a motor housing and retains a brush. The
method includes: forming a terminal integral part, which includes a
plurality of terminals and a coupling portion, wherein the coupling
portion couples the terminals with each other; molding a resin body
to embed the terminal integral part, wherein the resin body forms
at least part of the brush holder and has an opening from which the
coupling portion is exposed; separating the terminals from each
other by cutting the coupling portion, which is exposed from the
opening of the resin body; and coating the opening of the resin
body with a coating member to insulate the separated terminals from
each other.
[0009] The present invention also provides a brush holder. The
brush holder is located inside the motor housing and retains a
brush. The brush holder incorporates a terminal integral part,
which has a coupling portion. The coupling portion is located at a
predetermined position and couples the terminals with each other.
The brush holder has a resin body, a plurality of terminals and a
coating member. The resin body forms at least part of the brush
holder. The resin body has an opening. The terminals embedded in
the resin body. The terminals are coupled to each other by the
coupling portion as an integral part before being embedded in the
resin body. The coupling portion is exposed from the opening of the
resin body. The terminals are separated from each other by cutting
the coupling portion, which is exposed from the opening of the
resin body. The coating member coats the opening of the resin body
to insulate each terminal.
[0010] Other aspects and advantages of the invention will become
apparent from the following description, taken in conjunction with
the accompanying drawings, illustrating by way of example the
principles of the invention.
BRIEF DESCRIPTION OF THE DRAWINGS
[0011] The invention, together with objects and advantages thereof,
may best be understood by reference to the following description of
the presently preferred embodiments together with the accompanying
drawings in which:
[0012] FIG. 1 is a cross-sectional view illustrating a motor
according to a first embodiment of the present invention;
[0013] FIG. 2 is a partial cross-sectional view illustrating the
motor shown in FIG. 1;
[0014] FIG. 3 is a view illustrating the brush holder of the motor
in FIG. 1 from the direction indicated by an arrow A in FIG. 2;
[0015] FIG. 4 is a view illustrating the terminals located inside
the brush holder shown in FIG. 3;
[0016] FIG. 5 is a view illustrating a resin body, which forms the
brush folder shown in FIG. 3;
[0017] FIG. 6 is a view illustrating an integral part of the
terminals of the brush holder shown in FIG. 3;
[0018] FIG. 7 is a partial cross-sectional view illustrating a
modified embodiment of the motor;
[0019] FIG. 8 is a view illustrating the brush holder of the
modified embodiment of the motor shown in FIG. 7;
[0020] FIG. 9 is another view illustrating the brush holder shown
in FIG. 8;
[0021] FIG. 10 is still another view illustrating the brush holder
shown in FIG. 8; and
[0022] FIG. 11 is a view illustrating the sealing member of the
modified embodiment.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
[0023] A preferred embodiment of the present invention will now be
described with reference to FIGS. 1 to 6.
[0024] FIG. 1 shows a motor 1 of the preferred embodiment. The
motor 1 is used for a power source of a power window system
installed in a vehicle. The motor 1 includes a motor main body 2
and a reduction mechanism, which is a reduction gear 3.
[0025] The motor main body 2 includes a yoke housing member 4,
which forms part of a motor housing, a pair of magnets 5, armature
6, a brush holder 7, and a pair of brushes 8.
[0026] The yoke housing member 4 is an inverted cup-shaped member.
The pair of magnets 5 is secured to the inner circumferential
surface of the yoke housing member 4. The armature 6 is rotatably
accommodated inside the yoke housing member 4 radially inward of
the magnets 5. The armature 6 has a rotary shaft 9. The proximal
end of the rotary shaft 9 is rotatably supported by a bearing 10,
which is attached to the center of the ceiling of the yoke housing
member 4.
[0027] The yoke housing member 4 has an opening portion 4a. A pair
of flanges 4b extends radially outward from the opening portion 4a.
The yoke housing member 4 is secured to a gear housing member 21,
which will be described later, by the flanges 4b and bolts 11.
[0028] The brush holder 7 is held between the flanges 4b of the
yoke housing member 4 and an opening portion 21a of the gear
housing member 21 (see FIGS. 2 and 3).
[0029] The brush holder 7 has a holder main body 7a, an extended
portion 7b, and a connector portion 7c. The holder main body 7a
substantially closes the opening portion 4a of the yoke housing
member 4. The extended portion 7b extends radially outward from the
holder main body 7a. The connector portion 7c is exposed outside
the motor 1 from the extended portion 7b, and is electrically
connected to an outside device.
[0030] A clamping portion 7d, which is connected to the extended
portion 7b, is located around the outer circumferential portion of
the holder main body 7a. The clamping portion 7d is held between
the flanges 4b of the yoke housing member 4 and the opening portion
21a of the gear housing member 21 with the extended portion 7b.
[0031] A bearing 12 is attached to the substantial center of the
holder main body 7a. The bearing 12 rotatably supports a
predetermined portion of the distal end of the rotary shaft 9. A
brush retainer 7e is formed on the holder main body 7a to retain
the brushes 8. The brushes 8 slide against a commutator 13. The
commutator 13 rotates integrally with the rotary shaft 9.
[0032] An accommodating recess 7f is formed in the holder main body
7a. A substrate 14 is attached to the accommodating recess 7f. The
substrate 14 includes a pair of magnetometric sensors 15, which
have hall elements. A rotary body 24a of a clutch 24, which will be
described later, is coupled to the distal end of the rotary shaft 9
and rotates integrally with the rotary shaft 9. An annular sensor
magnet 16 is secured to the rotary body 24a. The sensor magnet 16
is multipolarised in the circumferential direction. The sensor
magnet 16 rotates integrally with the rotary shaft 9. The
magnetometric sensors 15 detect information (such as the number of
revolutions and the rotational speed) based on variation of the
magnetic field of the sensor magnet 16, which rotates integrally
with the rotary shaft 9.
[0033] As shown in FIGS. 3 and 4, six terminals 17 are embedded in
the holder main body 7a, the extended portion 7b, and the connector
portion 7c of the brush holder 7. Two of the terminals 17 are first
terminals 17a used for power supply and the other four terminals 17
are second terminals 17b used for sending out signals. The first
terminals 17a receive power supply from the outside, which then
supply the power to the brushes 8. The second terminals 17b send
out detection signals from the substrate 14 to the outside.
[0034] The first terminals 17a extend from the connector portion 7c
to a predetermined position of the holder main body 7a via the
extended portion 7b. The first terminals 17a are connected to the
brushes 8. The entire widths of the first terminals 17a are
substantially the same. The second terminals 17b extend from the
connector portion 7c to a predetermined position of the holder main
body 7a via the extended portion 7b. The second terminals 17b are
connected to the substrate 14. The widths of portions of the second
terminals 17b that are exposed inside an opening 7g of the
connector portion 7c are the same as the widths of the first
terminals 17a. The widths of other portions of the second terminals
17b that are embedded in the brush holder 7 are narrower than the
widths of the first terminals 17a. The first and second terminals
17a, 17b are located substantially parallel to each other at
predetermined intervals and insulated from each other.
[0035] The clamping portion 7d, the extended portion 7b, and the
connector portion 7c of the brush holder 7 are coated by a sealing
member 18. The sealing member 18 is formed of elastomer, which is
elastic and insulative. The sealing member 18 is sandwiched between
the opening portion 4a of the yoke housing member 4 and the opening
portion 21a of the gear housing member 21 to hermetically seal the
opening portions 4a and 21a. The sealing member 18 prevents foreign
objects, such as liquid and dust, from entering the yoke housing
member 4 and the year housing member 21. The sealing member 18 also
prevents foreign objects from entering the opening 7g of the
connector portion 7c.
[0036] The reduction gear 3 shown in FIG. 1 includes the gear
housing member 21, which forms part of the motor housing, a worm
shaft 22, a worm wheel 23, and the clutch 24. The gear housing
member 21 is made of resin and houses the worm shaft 22, the worm
wheel 23, and the clutch 24. The gear housing member 21 has the
opening portion 21a, which faces the opening portion 4a of the yoke
housing member 4. The gear housing member 21 and the yoke housing
member 4 are secured to each other by the bolts 11 with the brush
holder 7 sandwiched in between.
[0037] The worm shaft 22 is rotatably supported by bearings 25, 26
located at predetermined positions inside the gear housing member
21. The worm shaft 22 is coupled to the rotary shaft 9, which
extends from the motor main body 2, via the clutch 24. The clutch
24 transmits drive force of the rotary shaft 9 to the worm shaft 22
and locks rotation of the worm shaft 22 to prevent drive force from
being transmitted from the worm shaft 22 to the rotary shaft 9.
[0038] The worm shaft 22 is meshed with the worm wheel 23. The worm
wheel 23 is coupled to an output shaft 27, which is located
perpendicular to the axial direction of the worm shaft 22. The
output shaft 27 is coupled to an X-arm window regulator (not
shown), which selectively opens and closes a window glass (not
shown). When the output shaft 27 is rotated, the window regulator
is activated to selectively open and close the window glass.
[0039] The brush holder 7 according to the preferred embodiment
used in the motor 1 is manufactured as follows.
[0040] At first, a terminal integral part 30, which includes the
first and second terminals 17a, 17b as one unit as shown in FIG. 6,
is placed inside a first mold (not shown), which is used for
molding the brush holder 7. The terminal integral part 30 includes
first connecting portions 30a and second connecting portions 30b.
The first connecting portions 30a connect the second terminals 17b
with each other at a proximal end 7h of the connector portion 7c.
The second connecting portions 30b connect the first and second
terminals 17a, 17b with each other at the extended portion 7b of
the connector portion 7c. The terminal integral part 30 is formed
by punching a plate-like member, which is not shown, and folding
the plate-like member into a predetermined shape.
[0041] Then, resin is poured into the first mold in which the
terminal integral part 30 is placed. As shown in FIG. 5, a resin
body 31, which forms substantially the entire brush holder 7 (that
is, substantially the entire portion of the holder main body 7a,
the clamping portion 7d, the extended portion 7b, and the connector
portion 7c), is formed. First openings 31a and a second opening 31b
are formed in the resin body 31. The first connecting portions 30a
of the terminal integral part 30 are exposed from the first
openings 31a, and all the second connecting portions 30b are
exposed from the second opening 31b.
[0042] The resin body 31, which forms the brush holder 7, is
removed from the first mold. A tool (not shown) is inserted from
each of the first and second openings 31a, 31b of the resin body 31
to cut the corresponding first or second connecting portions 30a,
30b of the terminal integral part 30 (see FIG. 4). The second
connecting portions 30b are cut by a tool simultaneously. The first
and second terminals 17a, 17b are separated and insulated from each
other.
[0043] The resin body 31 is placed inside a second mold (not shown)
to mold the sealing member 18 from elastomer onto the resin body
31. Elastomer is poured into the second mold to form the sealing
member 18 integrally with the resin body 31, which forms the
clamping portion 7d of the brush holder 7, the extended portion 7b,
and the connector portion 7c. Elastomer, which forms the sealing
member 18, is simultaneously filled in the first openings 31a
located at the proximal end 7h of the connector portion 7c and the
second opening 31b of the extended portion 7b. This forms terminal
coating members 18a, which coat the first terminals 17a, and a
terminal coating member 18b, which coats the second terminals 17b
(see FIGS. 2 and 3). Each terminal coating member 18a or 18b
prevents the corresponding first or second terminals 17a, 17b from
being exposed from the corresponding first or second opening 31a,
31b. This prevents foreign objects, such as liquid or dust, from
entering inside the first and second openings 31a, 31b. Thus, each
first or second terminal 17a, 17b is prevented from being
short-circuited.
[0044] The terminal coating member 18b, which fills the second
opening 31b of the extended portion 7b, is sandwiched between the
left side flange 4b (as viewed in FIG. 2) of the yoke housing
member 4 and part of the gear housing member 21. Therefore, the
terminal coating member 18b is reliably prevented from falling
off.
[0045] The preferred embodiment provides the following
advantages.
[0046] The terminal coating members 18a, 18b are formed to coat the
first and second openings 31a, 31b of the resin body 31. Therefore,
the terminal coating members 18a, 18b reliably prevent foreign
objects from entering the first and second openings 31a, 31b where
the first and second terminals 17a, 17b are exposed. Therefore, the
first and second terminals 17a, 17b are reliably prevented from
being short-circuited by foreign objects.
[0047] The terminal coating members 18a, 18b are integrally formed
with the brush holder 7 and closely contact the opening portion 4a
of the yoke housing member 4 and the opening portion 21a of the
gear housing member 21. The terminal coating members 18a, 18b are
formed of the same material as the sealing member 18, which seals
the opening portions 4a, 21a. Therefore, the number of materials
that form the brush holder 7 does not increase. Also, the terminal
coating members 18a, 18b and the sealing member 18 can be made at
the same time if the materials are the same.
[0048] The first and second connecting portions 30a, 30b of the
terminal integral part 30 are formed at the extended portion 7b and
the connector portion 7c. In other words, the first and second
openings 31a, 31b need not be formed in the holder main body 7a to
cut the first and second connecting portions 30a, 30b. Therefore, a
space for arranging several components including the brushes 8 is
reliably obtained in the holder main body 7a. This increases the
flexibility of designing the brush holder 7.
[0049] The first and second connecting portions 30a, 30b of the
terminal integral part 30 are located on at least two portions,
which are the extended portion 7b and the connector portion 7c.
Therefore, the first and second terminals 17a, 17b of the terminal
integral part 30 are prevented from moving independently. This
facilitates handling of the terminal integral part 30.
[0050] The second connecting portions 30b are cut with a tool at
once. This facilitates cutting of the second connecting portions
30b.
[0051] The second opening 31b of the resin body 31 of the brush
holder 7 and the terminal coating member 18b, which coats the
second opening 31b, are arranged to be sandwiched between the yoke
housing member 4 and the gear housing member 21. Therefore, the
terminal coating member 18b is reliably prevented from falling off.
Thus, foreign objects are more reliably prevented from entering the
second opening 31b.
[0052] It should be apparent to those skilled in the art that the
present invention may be embodied in many other specific forms
without departing from the spirit or scope of the invention.
Particularly, it should be understood that the invention may be
embodied in the following forms.
[0053] The first and second connecting portions 30a, 30b of the
terminal integral part 30 may be located at only one of the holder
main body 7a, the extended portion 7b, and the connector portion
7c.
[0054] In the preferred embodiment, the first and second connecting
portions 30a, 30b are located at the extended portion 7b and the
connector portion 7c. However, the first and second connecting
portions 30a, 30b may be located at any two of the holder main body
7a, the extended portion 7b, and the connector portion 7c.
[0055] The terminal coating members 18a, 18b, and the sealing
member 18 may be made of different material. The terminal coating
members 18a, 18b, and the sealing member 18 need not be formed
simultaneously. The terminal coating members 18a, 18b may be made
of elastic material other than elastomer, or material other than
elastic material.
[0056] The structure of the brush holder 7 may be modified as
required. The manufacturing procedure of the brush holder 7 may
also be changed as required.
[0057] The sealing member 18 may be formed separately from the
resin body 31. That is, a molded sealing member may be attached to
a resin body afterwards (see FIGS. 7 to 11).
[0058] FIGS. 7 and 8 show a brush holder 35. As in the preferred
embodiment of FIGS. 1 to 6, the brush holder 35 includes a holder
main body 35a, an extended portion 35b, and a connector portion
35c. The holder main body 35a substantially closes the opening
portion 4a of the yoke housing member 4. The extended portion 35b
extends radially outward from the holder main body 35a. The
connector portion 35c is exposed outside the motor 1 from the
extended portion 35b, and is electrically connected to an outside
device. A clamping portion 35d is located around the outer
circumferential portion of the holder body 35a. The clamping
portion 35d extends from the extended portion 35b. The clamping
portion 35d is sandwiched between the flanges 4b of the yoke
housing member 4 and the opening portion 21a of the gear housing
member 21 with the extended portion 35b.
[0059] Two first terminals 36 used for power supply are embedded in
the holder main body 35a, the extended portion 35b, and the
connector portion 35c of the brush holder 35 as shown in FIG. 8.
The first terminals 36 extend from the connector portion 35c to a
predetermined position of the holder main body 35a via the extended
portion 35b, and are connected to brushes, which are not shown.
[0060] The brush holder 35 includes a resin body 40. As shown in
FIG. 9, the resin body 40 is formed by insert-molding a terminal
integral part 41. The terminal integral part 41 includes the first
terminals 36, which are connected to each other by a connecting
portion 41a. FIG. 8 shows a completed state of the brush holder 7.
FIG. 9 shows a state before first and second sealing members 37, 38
are attached to the brush holder 7 and before the connecting
portion 41a is cut. An engaging hole 40a, which exposes the
connecting portion 41a of the terminal integral part 41a, is formed
in the extended portion 35b of the resin body 40. After the resin
body 40 is molded, a tool (not shown) is inserted from the engaging
hole 40a to cut the connecting portion 41a. Thus, the first
terminals 36 are insulated from each other.
[0061] The pair of first and second sealing members 37, 38 is
attached to the clamping portion 35d and the extended portion 35b
of the brush holder 35 as shown in FIGS. 10 and 11. The first and
second sealing members 37, 38 are molded from elastomer, which is
elastic and insulative, separately from the resin body 40. The
first sealing member 37 closely contacts the opening portion 4a of
the yoke housing member 4, and the second sealing member 38 closely
contacts the opening portion 21a of the gear housing member 21. The
first and second sealing members 37, 38 are sandwiched between the
yoke housing member 4 and the gear housing member 21 so that the
openings 4a, 21a are hermitically sealed. This prevents foreign
objects, such as liquid and dust, from entering the yoke housing
member 4 and the gear housing member 21.
[0062] The first and second sealing members 37, 38 have terminal
coating members 37a, 38a, which hermetically seal the engaging hole
40a and prevent foreign objects from entering the engaging hole
40a. This prevents the first terminals 36 from causing
short-circuit. Projections 37b, 38b are formed on the terminal
coating members 37a, 38a, respectively. The projections 37b, 38b
fit with both openings of the engaging hole 40a. The projections
37b, 38b may be omitted. The terminal coating members 37a, 38a are
sandwiched between the left side flange 4b of the yoke housing
member 4 and part of the gear housing member 21 as shown in FIG. 7.
Therefore, the terminal coating members 37a, 38a are reliably
prevented from falling off. Although the sealing members 37, 38 are
attached to the resin body 40 as in the modified embodiment, the
same advantages as the preferred embodiment shown in FIGS. 1 to 6
are provided.
[0063] The structure of the motor 1 may be changed as required. For
example, the motor 1 may only include the motor main body 2, and
the reduction gear 3 may be omitted. Also, a substrate that forms a
control circuit for controlling the motor 1 may be provided.
[0064] Therefore, the present examples and embodiments are to be
considered as illustrative and not restrictive and the invention is
not to be limited to the details given herein, but may be modified
within the scope and equivalence of the appended claims.
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